So I'm making a game in AS3, it's a strategy DotA-like game (for flash game equivalent, there's UDE) so far so good, I have the A* pathfinding algorithm all sorted out and the minion units move to the desired location as I want them to be. The problem a rise when a unit stops in a node that has already occupied by another friendly unit. Both (or more than two) of them stacks up in one location, it looks like they're one unit.

I want to add collision detection so when they collide they don't stack up together. But now they stop when they collide on they way to a node. This isn't good because they won't move at all midway (they won't respond to enemy attacks like that). I've added a deltatime so they only stopped for 2 seconds before they move again to their designated designation. This moves them again but they flicker. Not how I want it.

So, like the title said. How to make more than one units don't stack up in a node? And if possible, how to make them not flicker while moving (it's good if they can tell other friendly units on the way and avoid them accordingly)?